Fatty acids play extensive roles in fetal energy metabolism and various physiological processes. Insufficient maternal supply of fatty acids increases the risk of intrauterine growth retardation (IUGR). Our previous research found that prenatal caffeine exposure (PCE) can lead to IUGR, but it is unclear whether this is related to placental fatty acid transport disorder. This study systematically investigates the impact of caffeine intake during pregnancy on placental fatty acid transport function and its molecular mechanisms by establishing rat models, mice intervention models, and in vitro cell experiments. In this study, we found that PCE reduces fatty acid levels in fetal blood, accompanied by decreased expression of placental fatty acid transporter 1 (FATP1) in rats. Further studies indicate that caffeine can antagonize ADORA2A and inhibit the expression and activity of the ERK-ETS1-PXR/RXRɑ signaling pathway in placental trophoblast cells. Conversely, ADORA2AR agonists, ETS1 overexpression plasmids, or PXR agonists can reverse the ADORA2A receptor antagonism, the decrease in ERK-ETS1-PXR/RXRɑ-FATP1 expression, and the disorder of fatty acid uptake caused by caffeine. Lastly, we confirmed that PXR agonists can reverse the reduction in placental FATP1 expression, fetal fatty acid levels, and birth weight observed in mice caused by PCE. In summary, this study elucidates the placental fatty acid transport mechanism mediated by the ADORA2A-ERK-ETS1-PXR/RXRɑ pathway inhibition in PCE-induced IUGR model, providing crucial theoretical basis and experimental support for clinical prevention and treatment research from the perspective of placental fatty acid transport.

Prenatal caffeine exposure (PCE) leads to intrauterine growth retardation and altered glucose homeostasis after birth, but the underlying mechanism remains unclear. This study aims to investigate the alteration of pancreatic development and insulin biosynthesis in the PCE female offspring and explore the intrauterine programming mechanism. Pregnant rats were orally treated with 120 mg/(kg∙day) of caffeine from gestational day (GD) 9 to 20. Results showed that fetal pancreatic β-cells in the PCE group exhibited reduced mass and impaired insulin synthesis function, as evidenced by decreased expression of developmental and functional genes and reduced pancreatic insulin content. At postnatal week (PW) 12, the PCE offspring exhibited glucose intolerance, diminished β-cell mass, and lower blood insulin levels. However, by PW28, glucose tolerance showed some improvement. Both in vivo and in vitro findings collectively indicated that excessive serum corticosterone (CORT) levels of the PCE fetuses may act through the activation of the pancreatic glucocorticoid receptor (GR) and recruitment of histone deacetylase 9 (HDAC9), leading to H3K9 deacetylation in promoter and downregulation of insulin-like growth factor 1 (IGF1), thereby inhibiting pancreatic islet morphogenesis and insulin synthesis in fetal rats. Furthermore, the PCE offspring after birth exhibited decreased blood CORT levels, increased H3K9 acetylation in promoter and upregulated gene expression of the pancreatic IGF1 promoter region, accompanied by elevated insulin biosynthesis. However, when exposed to chronic stress, the above changes were totally reversed. Conclusively, "glucocorticoid-insulin like growth factor 1 (GC-IGF1) axis" programming may be involved in pancreatic β-cell dysplasia and dysfunction in the PCE female offspring.

Nicotine, ethanol, and caffeine are the most common exogenous substances in the men's living environment, but their effects on the cartilage quality in the father and offspring have not been reported. According to the average daily intake of adult men, we constructed a male rat model of paternal mixed exposure (PME) to low-dose nicotine (0.1 mg/(kg·day)), ethanol (0.5 g/(kg·day)), and caffeine (7.5 mg/(kg·day)) for 8 weeks. Then, the male rats mated with normal female rats to obtain offspring. The results showed that PME reduced the cartilage quality of paternal and offspring rats. Among them, the paternal cartilage was damaged by enhancing matrix degradation, while the offspring cartilage was damaged by reducing matrix synthesis. The cartilage damage in male offspring rats was more evident than in female offspring. It was further confirmed that differential GC regulation mechanisms were the main reasons for the intergenerational differential damage of paternal/offspring cartilage quality caused by PME. In addition, the androgen receptor (AR) and estrogen receptor beta (ERβ) mediated the sex difference of PME-induced fetal cartilage dysplasia by affecting the binding degree of GR/P300. This study provided a theoretical and experimental basis for guiding male healthy lifestyle and exploring early prevention and treatment strategies for paternal diseases.

Caffeine intake during pregnancy is common, while its effect on gut microbiota composition of offspring and the relationship with susceptibility to adult diseases remains unclear. This study aimed to confirm the effects of prenatal caffeine exposure (PCE) on the gut microbiota composition and its metabolites in female offspring rats, and to further elucidate its underlying mechanism and intervention targets in adult non-alcoholic fatty disease (NAFLD). The results showed that the gut microbiota of PCE female offspring at multiple time points from infancy to adolescence were significantly changed with depletion of butyric acid-producing bacteria, leading to a decrease in butyric acid in adulthood. It was also found that PCE female offspring rats were sensitive to NAFLD induced by a postnatal high-fat diet (HFD), which is mainly related to the enhancement of hepatic triglyceride synthesis function. Through mechanism exploration, we found that HFD further reduced the fecal and serum butyric acid levels in the PCE female offspring, which was significantly negatively correlated with hepatic SREBP-1c/FASN mRNA expression and triglyceride level. In vivo and in vitro experiments confirmed that sodium butyrate (NaB) supplementation could reduce hepatic lipid accumulation through MCT1/GPR109A-AMPK, thereby effectively decreasing the susceptibility to NAFLD in the PCE female offspring rats.